Multiplexing of holograms based on spatial separation

The analysis of multiplexing methods using spatial separation has been carried out. It is shown that space division multiplexing is possible when there is no Bragg sampling action. The action of the Bragg sampling, its features for the cases of thin-layer flat holograms and in a sufficiently thick medium of volume holograms are considered separately. Among the methods of multiplexing using spatial selection, the methods of fractal type multiplexing and rotational multiplexing are considered. Fractal-type multiplexing allows, when used simultaneously with angular-type multiplexing, up to 6000 holograms to be recorded in one area, while the total volume of the storage medium remains the same. Rotational multiplexing is a special case of fractal type multiplexing. This type of multiplexing is especially effective for storing holograms in rather thin-layer media. Similar to fractal-type multiplexing, in this type of multiplexing, more than one hologram is simultaneously reconstructed by the required reference wave. However, only the result of the reconstruction of one hologram turns out to be unbiased and is fixed by the CCD matrix. The difference between this method and fractal-type multiplexing is that the offset in rotational multiplexing is the result of rotation of the storage medium.